1. Field of the Invention
The present invention relates to a system and a method for controlling a shift position when a vehicle travels along a steeply sloped road or a sharply curved road. More particularly, it relates to a system and a method for controlling a shift position when a vehicle travels along a steeply sloped road or a sharply curved road which may have a high efficiency of running in normal speed or reducing speed in response to a sloping or curving condition of a road.
2. Description of the Prior Art
In general, when a vehicle travels along an uphill road, more driving force is required than that when the vehicle runs on a level road. Accordingly, if the vehicle runs on the uphill road using an engine output or an ignition timing for running on the level road, the engine is overloaded and may easily become out of order.
In a vehicle having an automatic transmission, the vehicle running condition is dependent upon the condition of vehicle. However, the external condition of the vehicle has a great effect on the vehicle running.
For example, a relatively large torque is required when the vehicle travels uphill and a relatively small torque is required to travel downhill compared with that when the vehicle is running on the level road.
In addition, the acceleration is required after speed reduction for slow-in-fast-out on a sharply curved road.
The conventional art for the vehicle to run smoothly while compensating an injecting amount of fuel and an ignition timing according to the running condition of the vehicle in case of the vehicle running on the uphill road is disclosed in Korean Patent Application No. 93-27602 entitled "A system and a method for controlling operation of an engine when a vehicle turns on a sloped road".
According to the above techniques, in case that the downhill road - uphill road - downhill road are alternatively continued, although an accelerator pedal is released to reduce vehicle speed for travelling along the downhill road after travelling along the uphill road the vehicle speed is still accelerated since an up-shift state remains.
In addition, although the accelerator pedal is released in case of the vehicle is travelling along the sharply curved road without reducing the vehicle speed, the vehicle speed is still accelerated and the vehicle is pushed out of a turning direction by centrifugal force since up-shift state still remains.